1. Field of the Invention
The invention concerns a method and a apparatus for the production of synthesis gas from gaseous hydrocarbons by means of allothermal steam reforming with catalysts.
2. Description of Related Art
As resources are becoming ever more limited and more costly and energy demand is rising worldwide, all processes in the field of energy conversion must be made more compact, efficient and decentral. This applies in particular to the generation of electricity and heat and for propulsion of vehicles. Thus for example by converting primary energy into hydrogen, and decentral energy conversion by means of a cogeneration of heat and power using fuel cells, a very high yield of useful energy can be achieved. Around half the useful energy is released in the form of electrical energy. This is far more than needed today. Power and heat in this system have almost equivalent value. Details are described in the book by Tetzlaff “Wasserstoff für elle” [“Hydrogen for all”] (ISBN 978-38370-6116-1).
Allothermal gasification methods generate a particularly high quality synthesis gas. As this is an endothermic reaction, the necessary thermal energy must be introduced by heat transfer into the reaction chamber. The necessary heat is generated by combustion of hydrocarbons with air or oxygen.
A typical apparatus of this type consists of a box-like furnace which is fitted with a plurality of tubes filled with nickel-containing catalyst pellets. On the top of this furnace is a plurality of burner nozzles arranged between the tubes. To prevent local overheating, a large distance from the burner flame to the tubes must be maintained. Both flue gases and the hydrocarbons to be gasified in the tubes flow in a direct current from top to bottom.
The apparatuss of the prior art require a great deal of space and always generate an exhaust gas which must be cleared of air pollutants in a complex manner. Such systems can only be approved at great expense in densely populated modern states. As the reaction takes place at temperatures between 820° C. and 920° C., a large part of the energy introduced is lost through the exhaust gas.